Temperature compensated gas meter register

ABSTRACT

A gas meter assembly wherein a positive displacement meter disposed in a conduit through which flows gas to be measured is connected through a gear transmission unit to drive both corrected and uncorrected volume indicating registers, the unit comprising an initial gear train common to the drive to both registers, a first branch gear train connecting the initial gear train to the uncorrected register, a second branch gear train connecting the initial gear train to a shaft in the drive to the corrected register and a cam actuated unidirectional clutch connected to impart additive rotation to that shaft in accord with the gas temperature in the conduit, for continually automatically modifying the drive to said corrected register to correct the indicated volume to a predetermined base temperature.

0 United States Patent [191 [111 3,733,904 Bonner et al. 14 1 May 22,1973 [54-1 TEMPERATURE COMPENSATED GAS 2,886,969 5/1959 Dufour ..73/233METER REGISTER Primary Examiner-Richard C. Queisser [75] InventorsJoseph Bonner Pmsfburgh Assistant Examiner-John P.'Beauchamp Howard J.Evans, New Kensmgton, Attome Stm h Nolan Neale & K both of Pa. yug urz[73] Assignee: Rockwell Manufacturing Company, [57] ABSTRACT PittsburghA gas meter assembly wherein a positive displacement [22] Filed: Jan. 4,1971 meter disposed in a conduit through which flows gas to be measuredis connected through a gear transmis- [211 Appl' 103365 sion unit todrive both corrected and uncorrected volume indicating registers, theunit comprising an ini- [52] US. Cl ..73/233 tial gear train common tothe drive to both registers, a [51] Int. Cl. ..G0lf 3/00, FOlf 15/04first branch gear train connecting the initial gear train [58] Field ofSearch ..73/233 to the uncorrected register, a second branch gear trainconnecting the initial gear train to a shaft in the drive [56]References Cited to the corrected register and a cam actuatedunidirectional clutch connected to impart additive UNITED STATES PATENTSrotation to that shaft in accord with the gas tempera- 3,224,273 12/1965Granberg ..73 233 We in the conduit, for continually automatically3,580,073 5/1971 Siebold ..73/233 ying h drive o said corrected registerto cor- 3,299,705 1/1967 Shallenberg et al.. ..73/233 rect the indicatedvolume to a predetermined base 3,169,399 2/1965 Allport et al. ..73/233temperature, 1,881,572 10/1932- Herz ..73/233 2,302,529 11/1942 Cornellet al. ..73/233 X 9 Claims, 8 Drawing Figures PATENTED HAY 2 2 I975SHEET 1 UF 4 INVENTORS JOSEPH A. BONNER HOWARD J, EVANS MW ATTORNEY:

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INVENTORS JOSEPH A. BONNER HOWARD J. EVANS BY JQM aw ATTORN sPAINTED-#1221975 SHEET 3 [IF 4 INVENTORS JOSEPH A. BONNEQ HOWARD J.EVANS ATTORNEYS PATENTEB 1W2 2 I975 SHEET 5 BF 4 INVENTOR JOSEPH A.BONNER HOWARD J. EVANS A 0 NE TEMPERATURE COMPENSATED GAS METER REGISTERThis invention relates to fluid meter register apparatus, andparticularly to gas meter register apparatus wherein motion transmittingmechanism between a meter and a register is automatically corrected torelate the volume indication of the register to a base temperature.

BACKGROUND OF THE INVENTION In the conventional gas meter the meteroutput shaft is connected by suitable motion conversion mechanism toactuate a register which records volume of gas flow, usually in cubicfeet.

Gas is conducted to and from the meter in a conduit, and the temperatureof the gas being metered may vary from time to time. It therefore forthe sake of uniformity and accuracy has long been the practice tocorrect reading of the register to indicate the volume of gas passingthrough a meter with reference to a base temperature, usually about 60F. Such prior practice may be noted by reference to U.S. Pat. No.1,881,572 issued Oct. 11, 1932 to Herz. More recently temperaturecompensated gas volume registration has been disclosed in U.S. Pat. No.3,169,399 issued Feb. 16, 1965 to Allport et al. Other patentsdisclosing different modes of temperatures compensation in gas metersare Ruffer U.S. Pat. No. 3,266,310 and Rose U.S. Pat. Nos. 3,334,519 and3,358,506.

The present invention provides novel apparatus that representsimprovement and simplicity with respect to the foregoing, and whereinthe meter output is connected to a register through a drive mechanismunit that may be continually modified by improved control meansresponsive to the temperature of the gas being metered to reliablycontinually correct the register indicated volume to a base temperature,and this is the major object.

Another object of the invention is to provide a novel gas meteringapparatus wherein a cam controlled unidirectional clutch means drivenfrom the meter imparts periodic compensative movement to a meter drivenshaft in a register drive system and means responsive to the temperatureof the gas being metered controls the amplitude of such movement tocorrect the volumetric indication of the register to a base temperature.

A further object of the invention is to provide a novel meter registerdrive wherein a shaft connected to actuate the register is gearedsubstantially directly to the meter output and a temperaturecompensating drive derived from the meter output and automaticallycontinually modified in accord with the temperature of the gas beingmetered is connected to impart additive movement to the shaft forcorrecting the volumetric indication of the register to a basetemperature.

It is an object of the invention to provide in a temperaturecompensating drive between a meter and a shaft in the register drivesystem novel mechanism comprising a unidirectional clutch connected tothe shaft and actuated by a lever that is periodically rocked by a camdriven from the meter, the amplitude of rocking being determined by adevice positioned in response to the temperature of the gas beingmetered. More specifically this device may be a stop for limiting springbiased movement of said lever toward the cam.

Another object of the invention is to provide in a drive system betweena positive displacement gas meter and volume indicating register means anovel drive gear unit having an input connected to the meter outputshaft and separate outputs connected to corrected and uncorrectedvolumetric registers, compensating mechanism for the corrected registerbeing carried by the gear unit and connected to be controlled bytemperature sensitive means exposed to the gas being metered.

Further objects of the invention will appear as the specificationproceedsin connection with the drawings, particularly as to details suchas the provision of a special gear unit in the register drive, theadjustable movable connecting mechanism between the lever stop and asuitable temperature sensitive element, and the various relatedmountings and operative associations of the parts to be described.

BRIEF DESCRIPTION OF DRAWINGS FIG. I is a diagrammatic view illustratinga register drive system for a gas meter assembly according to apreferred embodiment of the invention;

FIG. 2 is a front view of the register assembly;

FIG. 3 is an enlarged section substantially on line 3-3 of FIG. 2showing internal detail of the drive to the corrected and uncorrectedregisters;

FIG. 3A is a fragmentary view in section comprising an effectiveextension of FIG. 3 showing the shielded end of the thermally sensitiveunit within the flow conduit;

FIG. 4 is a section showing detail of the transmission gearing assemblyunit;

FIG. 4A is a fragmentary section showing an extension of the FIG. 4gearing unit to the drive for the uncorrected register;

FIG. 5 is a section substantially on line 5-5 of FIG. 3 showing thegearing arrangement; and

FIG. 6 is a section substantially on line 6-6 of FIG. 3 showing thetemperature compensation mechanism in the corrected drive.

PREFERRED EMBODIMENTS FIG. 1 diagrammatically illustrates the novelassociation of system components according to a preferred embodiment ofthe invention.

The front side of the register assembly indicated at 11 in FIG. 2displays the uncorrected register R and the corrected register Rc. Theseregisters record fluid flow through the conduit 12 which drives themeter'device M therein.

Meter device M is preferably of the positive displacement type, andadvantageously may be the meter disclosed in Karlby et al. U.S. Pat. No.3,255,630 issued June 14, 1966.

Referring to FIGS. 1, 4 and 4A driven shaft means 13 at the meter outputenters the transmission gear assembly unit 10 of the register assemblyat a first or input gear 14. Gear 14 is connected by meshed gears 15,16, and 17 within the space between fixedly connected parallel mountingplates 18 and 19 of the transmission assembly unit to a gear 20 on arotatable shaft 21 that projects through plate 18 to mount a calibrationgear 22. Gear 22 is meshed with a second calibration gear 23 on aparallel rotatable shaft 24 that extends through both plates 18 and 19to mount a gear 25 within the space and an eccentric cam 26 outsideplate 19. The calibration gears 22,23 may be substituted for by a pairof gears providing a different ratio drive to the registers, duringinitial calibration of the assembly.

Gear 25 meshes with a gear train 27, 28, 29, and 31 within thetransmission assembly space, gear 31 being mounted on and connected torotate a shaft 32 through a conventional one-way clutch 33. Shaft 32which is supported in unit 10 also carries a gear 34 meshed with a gear35 fixed on rotatable output shaft 36 that drives the compensatedregister Rc. As shown in FIGS. 4A and a gear 37 which is also meshedwith gear 27 is meshed with gear 38 fixed on rotatable output shaft 39that drives'the uncorrected register. Gears 38 and 39 are not shown indiagrammatic FIG. 1. The drive connections between shafts 36 and 39 andthe respective registers are conventional.

As diagrammatically shown in FIG. 1, eccentric cam 26 during rotationperiodically rocks a lever 41 connected through a second unidirectionaldrive clutch 42 to shaft 32. Lever 41 and cam 26 are shown 90 displacedfor clarity of illustration of function Clutches 33 and 42 may be of anyconventional type such as the ball wedge type disclosed in Marsh US.Pat. No. 2,438,934, and they are adapted to impart the same direction ofrotation to shaft 32.

Return of lever 41 by spring 43 is limited by a stop assembly 44positioned by a rockable actuating arm 45, that may alter the locationof the stop relative to lever 41 through means including a probe 46 thatextends into the conduit 12 and is thus responsive continuously to thetemperature of the fluid being metered.

Referring to FIG. 3, the register assembly 11 is mounted on a plate 48that may be suitably secured over an opening in the side of conduit 12.A base 49 defining a chamber 51 is secured on plate 48, and a cupshapedcasing 52 is secured upon the base to define a mechanism chamber 53. Thegear assembly unit is suitably fixedly but removably mounted in chamber53 as by supports 50 (FIG. 3) suitably rigid with base 49. Plates 18 and19 are fixedly spaced by posts 54.

Meter driven shaft means 13 which constitutes the input to the registerdrive system comprises a shaft 55 connected by a fluid tight magneticdrive unit 56 to a shaft bearing input gear 14. The drive unit comprisesa shaft 57 carrying a drive magnet 58 housed by a fixed well 59 ofnon-magnetic material, and a cooperating driven magnet 61 mounted on arotatable shaft 62 carrying gear 14.

The probe for controlling the stroke of lever 41 may comprise atemperature'sensitive element 63 preferably in the form of a coiledBourdon tube surrounded by a protective shell 64 and extending through ashield 65 attached to the bottom of plate 48 and projecting withinconduit 12. Shell 64 has one end fixed in a fitting 66 rigid with base49. Element 63 is of a known type per se that upon change in temperatureof the fluid contacting it produces proportional rotation of an attachedshaft 67 about its longitudinal axis.

The reduced diameter end of shaft'67 extends through a bushing 69 liningan opening in a mounting plate 71 removably secured to base 49 as byscrews 72. Shaft 62 of the meter drive extends freely through a suitableopening 73 in plate 71.

As shown in FIGS. 3 and 6, shaft end 68 extends into an opening in theactuating arm 45 and is non-rotatably fixed to arm 45 as by set screw75. By releasing screw 75 the angular position of arm 45 on shaft 67 maybe adjusted. The stop assembly 44 comprises an adjustable link unit 76consisting of a link 77 formed at one end with a threaded bore rotatablyadjustably mounting a threaded pivot member 78 which carries a pivot 79for pivotally connecting arm 45 in eccentric relation to the axis ofshaft 67.

As shown in FIG. 6, clutch lever 41 extends from shaft 32 and carries afreely rotatable follower roller 81 that is constantly urged by spring43 against the periphery of eccentric cam 26. Spring 43 is a tensionspring anchored at opposite ends on lever 41 and plate 19.

Intermediate it ends lever 41 has a fixed laterally projecting guide pin82 slidably disposed in the slotted or bifurcated upper end 83 of link77. A transverse end surface 84 on link 74 acts as a stop surfaceadapted to be abutted by the lower surface 85 of lever 41 duringoperation. Adjustment of member 78 may be effected by detaching it fromarm 45 and rotating it in its threaded bore. This adjustment will varythe effective length L of the link for determining the distance of stopsurface 84 from arm 45.

Preferrably pivot 79 is carried by a block 86 slidably adjustable alonga slot 87 in arm 45, and the distance d between the center of rotationof shaft 67 and the pivot 79 may be adjusted by a set screw88 threadedin arm 45 and in block 86. This adjustment varies the amount ofdisplacement of stop surface 84 per degree of rotation of shaft 67. Theangular adjustment of arm 45, and length adjustment of link 77 and theadjustment of pivot 79 are all calibration adjustments for th meterassembly.

A fixed dial 91 is associated with an indicator lever 92 having an index93 adjacent the graduated dial periphery. Lever 92 is intermediatelypivoted at 94 and has an end pivotably connected to a stud 95 secured toand movable longitudinally with link 77. The periphery of dial 91 ispreferrably graduated to show temperature in degrees Centigrade.

In brief in operation meter shaft means 13 is rotated by gas flowing inconduit 12. Drive is transmitted through gears 14, 15, 16, 17, 20, shaft21, calibration gears 22 and 23, shaft 24 and gear 25 to gear 27. Thisinitial gear train of the gear unit 10 is common to the drive to bothregisters. The uncorrected register R is driven from gear 27 through afirst branch train comprising gears 37 and 38 and shaft 39. Thecorrected register Rc is driven from gear 27 through a second branchtrain comprising gears 28, 29 and 31, clutch 33, shaft 32, gears 34 and35 and shaft 36.

The drive to the corrected register is continually modified. Cam 26driven by the initial portion of the gear train periodically rocks lever41 in a direction to impart an increment of rotation to shaft 32,additive to the continuous rotation being imparted by the second branchgear train. Lever 41 is spring biased for return movement during whichit imparts no rotation to shaft 32.

The stop 44 of FIG. 1, or more specifically the stop I surface 84 of thelink 77 of FIG. 6, is positioned by the thermally responsive means at apoint in the path of return movement of lever 41 in accord with thetemperature of the gas being metered. This is accomplished by thermallysensitive element 63 acting in response to the gas temperature toangularly locate arm 45 and therefore position link 77 at acorresponding level in the return path of lever 41.

The dimensions and arrangement are such that should the gas temperaturein the conduit be 60 F., or

any other selected base temperature, surface 84 will be disposed tocontact lever 41 at such a level as to permit an amplitude of rockingsuch that just enough additive rotation will be imparted to shaft 32 sothat both the corrected and uncorrected registers will have the samevolumetric reading. In a preferred embodiment, a gas temperature ofabout 120 F. in the conduit will result in such upward displacement ofthe stop 84 that the follower 81 of lever 41 will contact the rotatingcam for only a limited arc of the cams travel and at a curvature on theperiphery of the cam which is such that it will not rock the lever 41 ata rate greater than the rate of rotation of clutch 33 and, therefore, noadditive movement will be imparted to shaft 32, wherefore the volumetricreading at the corrected register will be low. Where the gas temperaturefalls below 60 F. the corrected register will show a proportionatelylarger volume due to the added effective stroke action of lever 41.

It is recognized that variations in gas pressure in the conduit willaffect the volumetric readings at the registers, but the above-describedmeter assembly is intended for use in a relatively main gas line whereinpressures are reliably held fairly constant, at least within acceptableunits. This pressure is usually monitored and recorded, and after areading is taken at the registers a suitable correction factor tocorrect to a selected base pressure may be applied.

For practical purposes therefore, the temperature compensated gas meterassembly herein described is adequate, and is considerably lessexpensive than the relatively complex assemblies which endeavored tocorrect volume for both pressure and temperature.

The invention may be embodied in other specific forms without departingfrom the spirit or essential characteristics thereof. The presentembodiments are therefore to be considered in all respects asillustrative and not restrictive, the scope of the invention beingindicated by the appended claims rather than by the foregoingdescription, and all changes which come within the meaning and range ofequivalency of the claims are therefore intended to be embraced therein.

What is claimed and desired to be secured by Letters Patent is:

1. In a meter assembly for measuring the volume of gas corrected to apredetermined base temperature, a cummulative volume indicatingregister; a gear transmission unit interposed between said register anda meter disposed in a conduit through which flows the gas to bemeasured, said unit including a shaft connected to be continuouslyrotated in a predetermined direction by said meter; compensating meanscomprising a continuously rotatable cam connected to be driven from saidunit and a lever periodically rockably moved by said cam and connectedto said shaft for imparting added rotational movement to said shaft insaid predetermined direction; and means responsive to the temperature ofthe gas being metered for continually controlling the degree of saidadded rotational movement, said temperature responsive means comprisingan arm rockable about a fixed pivot, thermally sensitive means exposedto the gas being measured and connected to angularly rock said arm upona change in temperature of said gas, a link pivoted at one end to saidarm eccentrically with respect to said fixed pivot and having a stopsurface at its other end adapted to be engaged by said lever, andadjustment means for said link to adjust said stop surface to apredetermined initial position with respect to said lever.

2. In the meter assembly defined in claim 1, said other end of said linkhaving a slide pivot connection to said lever adjacent said stopsurface.

3. In the meter assembly defined in claim 1, said adjustment meansincluding means for adjusting the angularity of said arm about its fixedpivot.

4. In the meter assembly defined in claim 1, said adjustment meansincluding means for adjusting the distance between said fixed pivot ofsaid arm and the pivotal connection of said arm to said link.

5. In the meter assembly defined in claim 1, said adjustment meansincluding means for adjusting the effective length of said link betweensaid arm and said stop surface.

6. In the meter assembly defined in claim 1, temperature indicatingmeans operably connected to said link for indicating the temperature ofthe gas being metered.

7. In a gas meter assembly of the type wherein the output of a positivedisplacement meter disposed in a conduit through which flows gas to bemeasured is connected through a gear transmission unit to drive bothcorrected and uncorrected volume indicating registers, said unitcomprising an initial gear train common to the drive to both registers,a first branch gear train connecting said initial gear train to drivethe uncorrected register, a second branch gear train driven from saidinitial gear train, a rotatable shaft drive connected to the correctedregister, a first unidirectional clutch on said shaft drive connectingsaid second branch gear train to said shaft to rotate said shaft in apredetermined direction, and compensating means driven from said initialgear train and controlled by the gas temperature in said conduit forcontinually automatically modifying the drive through said second branchgear train to said rotatable shaft and corrected register to correct theindicated volume to a predetermined base temperature, said compensatingmeans including a second unidirectional clutch on said shaft, a drivemechanism connecting said initial gear train to said second clutch forimparting added rotational movement to said shaft in said predetermineddirection, and thermally sensitive means responsive to the temperatureof the gas being metered for continually controlling the degree of saidadded rotational movement.

8. In the gas meter assembly defined in claim 7, said initial gear trainincluding a pair of meshed gears disposed to be readily removable andreplaceable by another pair of meshed gears having a different ratio,for meter calibration.

9. In a gas meter assembly as defined in claim 7, said mechanismcomprising a cam driven by said initial gear train and a follower leverconnecting the cam to the second unidirectional clutch, and meansconnected to be positioned by said thermally sensitive means andoperatively associated with said lever for determining the increment ofrotation imparted thereby to said shaft.

1. In a meter assembly for measuring the volume of gas corrected to apredetermined base temperature, a cummulative volume indicatingregister; a gear transmission unit interposed between said register anda meter disposed in a conduit through which flows the gas to bemeasured, said unit including a shaft connected to be continuouslyrotated in a predetermined direction by said meter; compensating meanscomprising a continuously rotatable cam connected to be driven from saidunit and a lever periodically rockably moved by said cam and connectedto said shaft for imparting added rotational movement to said shaft insaid predetermined direction; and means responsive to the temperature ofthe gas being metered for continually controlling the degree of saidadded rotational movement, said temperature responsive means comprisingan arm rockable about a fixed pivot, thermally sensitive means exposedto the gas being measured and connected to angularly rock said arm upona change in temperature of said gas, a link pivoted at one end to saidarm eccentrically with respect to said fixed pivot and having a stopsurface at its other end adapted to be engaged by said lever, andadjustment means for said link to adjust said stop surface to apredetermined initial position with respect to said lever.
 2. In themeter assembly defined in claim 1, said other end of said link having aslide pivot connection to said lever adjacent said stop surface.
 3. Inthe meter assembly defined in claim 1, said adjustment means includingmeans for adjusting the angularity of said arm about its fixed pivot. 4.In the meter assembly defined in claim 1, said adjustment meansincluding means for adjusting the distance between said fixed pivot ofsaid arm and the pivotal connection of said arm to said link.
 5. In themeter assembly defined in claim 1, said adjustment means including meansfor adjusting the effective length of said link between said arm andsaid stop surface.
 6. In the meter assembly defined in claim 1,temperature indicating means operably connected to said link forindicating the temperature of the gas being metered.
 7. In a gas meterassembly of the type wherein the output of a positive displacement meterdisposed in a conduit through which flows gas to be measured isconnected through a gear transmission unit to drive both corrected anduncorrected volume indicating registers, said unit comprising an initialgear train common to the drive to both registers, a first branch geartrain connecting said initial gear train to drive the uncorrectedregister, a second branch gear train driven from said initial geartrain, a rotatable shaft drive connected to the corrected register, afirst unidirectional clutch on said shaft drive connecting said secOndbranch gear train to said shaft to rotate said shaft in a predetermineddirection, and compensating means driven from said initial gear trainand controlled by the gas temperature in said conduit for continuallyautomatically modifying the drive through said second branch gear trainto said rotatable shaft and corrected register to correct the indicatedvolume to a predetermined base temperature, said compensating meansincluding a second unidirectional clutch on said shaft, a drivemechanism connecting said initial gear train to said second clutch forimparting added rotational movement to said shaft in said predetermineddirection, and thermally sensitive means responsive to the temperatureof the gas being metered for continually controlling the degree of saidadded rotational movement.
 8. In the gas meter assembly defined in claim7, said initial gear train including a pair of meshed gears disposed tobe readily removable and replaceable by another pair of meshed gearshaving a different ratio, for meter calibration.
 9. In a gas meterassembly as defined in claim 7, said mechanism comprising a cam drivenby said initial gear train and a follower lever connecting the cam tothe second unidirectional clutch, and means connected to be positionedby said thermally sensitive means and operatively associated with saidlever for determining the increment of rotation imparted thereby to saidshaft.